Investigation of syphilis coinfection and performance of the Architect Syphilis Tp ELISA screening test in HIV positive patients

Abstract

Background/aim: Limited data on syphilis coinfection in human immunodeficiency virus (HIV) positive cases exist in Turkey. Our aim is to investigate syphilis coinfection and to evaluate the compatibility of the screening Architect Syphilis Tp ELISA with the fluorescent treponemal antibody absorption (FTA-abs) confirmation test in HIV positive cases.

Materials and methods: Totally 519 HIV positive patients were included in the study. Enzyme linked fluorescent assay (ELFA) was used as a screening test and positive samples were confirmed by line immunassay (LIA). In order to discriminate acute HIV infection and false ELISA positivity, HIV-1 RNA PCR was performed in ELFA positive and LIA negative samples. Architect Syphilis TP ELISA was used for the detection of total antibodies against Treponema pallidum in HIV positive patients. Positive results were confirmed by the FTA-abs test.

Results: Out of 519 HIV-1 positive patients, IgG and IgM positivity, and only IgG positivity was detected as 1.9% and 11.4% in all the samples, respectively. A total of 79 (15.2%) sera were positive with Architect Syphilis Tp ELISA test and 69 (13.3%) were positive with FTA-abs test. Statistically significant, almost perfect agreement was found between Architect Syphilis Tp ELISA and FTA-abs tests (kappa = 0.921 and P < 0.001).

Conclusion: Implementation of syphilis and HIV screening tests together among risk groups is considered to be appropriate.

Keywords: Syphilis; HIV/AIDS; coinfection.